Abstract

We fabricated high-quality strain-relaxed thin SiGe layers by Ar ion implantation into Si substrates before epitaxial growth. The surface of 100-nm-thick layers, the relaxation ratio of which was more than 80%, was found to be very smooth, with a rms roughness of 0.34 nm. Cross-sectional transmission electron microscopy analysis confirmed that strain-relieving dislocations were effectively generated due to the ion-implantation-induced defects and confined in the vicinity of the heterointerface, resulting in a dislocation-free SiGe surface. Moreover, in-plane strain-field fluctuation was found to be largely reduced by this ion implantation method.

Received 19 March 2004Accepted 28 July 2004Published online 28 September 2004

Acknowledgments:

The authors wish to thank S. Otake for his technical support. This work was supported in part by a Grant-in-Aid for Scientific Research on Priority Area (No. 11232202) from the Ministry of Education, Culture, Sports, Science and Technology.